Little Big Sister
by Blonde Panther
Summary: FE13, for Chrobinweek day 5- Morgan and Lucina. On her sixteenth birthday, Princess Lucina realises there is a bruise on her ankle that wasn't there before. When it starts to change shape, Chrom suspects his Chief Tactician may know more about it.


**Disclaimer:** Fire Emblem and all names and concepts belong to Nintendo and Intelligent Systems.  
 **Characters and Pairings:** Chrom, mentions of Chrom/Robin, Lucina, Morgan.  
 _ **Author's Notes:**_ _I… guess this isn't so much Chrobin as it is Morgan and Lucina, but that was today's prompt, after all. Although I suppose it could also fit for 'Branded and Marked,' but that wasn't the intention. Basically, 'Big Morgan and Little Lucina' is a concept I'm fond of, and I wanted to try my hand at it sometime._

* * *

 _ **Little Big Sister**_

Ylisse's young princess had slept poorly that night. She never slept well on the night before her birthday. One'd think she would've grown out of that by now, turning sixteen, but she hadn't. A day on which neither she nor her father would have to worry about any formalities or responsibilities… she always looked forward to it. Aunt Lissa and Sir Frederick would take over most of her father's responsibilities so he could spend the day with his daughter. She didn't know what they would do yet -ride, practice swordplay, or just go into the city together- but it was a happy change of pace around the palace.

"Ow!" she jolted when her attendant ran across a nasty tangle in her hair. "Severa!"

"Stop whining!" the black-haired girl said, although her voice didn't carry the sting it did when she said it to other people. Despite her prickly nature, Lucina considered Severa to be one of her dearest friends. It was the reason she'd requested that Severa, and not Cynthia or Kjelle, be made her personal attendant. Dame Cordelia had been proud of her daughter, but Lucina couldn't for the life of her remember how Severa's father had reacted. …or even what he looked like. Point was, Severa was no-nonsense and got stuff done, but at the same time she was good at listening when that was needed, and her confident, sometimes self-centered nature somehow never interfered with her service to Lucina. "It's not my fault your hair decided to be a total nightmare today. How do you want to wear it, by the way?"

"Just braid it," Lucina said, without missing a beat. "I don't know how Father wants to spend the day, but it can never hurt to have my hair as restrained as it can get, right?" Severa sighed and Lucina looked at her sheepishly in the mirror. "I'm sorry…" her hair was tough, thick, and generally uncooperative.

Still, Severa sighed and rolled up her sleeves. "If I can make an updo for formal events, I can braid it," she said. "No guarantees this won't hurt, though." With that, she parted her liege's hair into threes and started placing the strands over one another rhythmically, interjecting every new part with a sharp tug to the strand to make sure the braid would remain tight and neat. Lucina winced every time. Sometimes, Severa was the embodiment of 'tough love.' "So," the attendant said between braids, "Apart from your father-daughter time, is there anything else that'll go on for your birthday?"

"Well there's the banquet next week, obviously," Lucina said. "What with my coming of legal age and all."

"Neat," Severa said. It meant she got to do complex things with Lucina's hair, dress, jewelry, scent, and general appearance. To Lucina's horror, when she tied off the braid, she leaned forward and made her best teasing face. "Do you think Laaaaaaaaurent will be in attendance?"

"Severa!" Beet red, Lucina wasted no time reaching for the closest thing on her vanity –her hairbrush- and throwing it at her attendant. "I told you that in confidence!"

"I didn't tell anyone else!" Severa protested, catching the brush effortlessly. "Besides, he really might be there. His Grace will probably want a shitload of guards around for his pwecious little girl's birthday, and who better to keep hungry men away from you than Sir Frederick's little prodigy?"

Lucina shrugged. "Laurent is more of a scholar than a knight," she protested, "and you know it. Either Father would be _very_ desperate, Sir Frederick _very_ convincing, or Laurent interested in me as well for him to be there."

"Honestly, I'm giving you good chances on at least two of those."

"Just get my clothes, would you."

"Yes, milady."

Once fully dressed for the day, Lucina made her way to the dining hall where she would meet her father over breakfast, but stopped in the doorway when she saw him. He hadn't had his breakfast yet –she knew he was waiting for her to have it brought in- but he wasn't alone. He was bent over a batch of papers, maps, and notebooks, accompanied by a man only a few years younger than him, sporting a mop of dark blue hair and, Lucina knew, dark brown eyes. Most of his body was always concealed under a thick, dark coat sporting a high, stiff collar, and today was no exception.

She pouted a little. Honestly! Morgan could -always- consult her father on anything. But out of all the days in the year, did he have to bother him today? Most trusted advisor, Chief Tactician, and close personal friend or not, surely he understood that Lucina's birthday was special! She coughed to get their attention, and while her father was still captivated by something on the map, Morgan looked up. "Oh," he said, eyes widening with realization. "Oh!" He scrambled to gather his papers, prompting Chrom to look up as well. "It looks like I've imposed on you too much, Your Grace," he said as he stacked his papers and aligned them. "We can continue this later." With that, he stood up and hurried towards the door, bowing to Lucina as he passed her. "Happy birthday, Princess Lucina."

"Thank you," she said, smiling despite herself. Although he was closer with her father than with her, Morgan had always been kind to her, never stingy with his smiles or friendly words. He'd even tutored her in basic strategy for a little while and attempted to teach her a little magic before they realized she was hopeless with a tome. Something about the way he looked at her had always been a little strange, and for a short time her cousin Owain, with his overactive imagination, had sworn that Morgan had an illicit and inappropriate crush on her, but Lucina wasn't so sure. It felt… different. It wasn't unlike the way her father looked at her and treated her.

For now, she settled for it being very 'Morgan' of him as she watched him leave, before sitting down with her father- but not before running over to him and hugging him tightly. "Hey sweetheart!" he said, returning her eager hug. "Happy birthday!"

Morgan had had to stop not far from the dining hall because one of his notebooks had threatened to slip, and he looked at the two over his shoulder with a fond smile. Sixteen years, he thought, had it really been that long? Well, more of fifteen years, he supposed, since they had returned to Ylisstol victorious shortly before Lucina's first birthday. Fifteen years then, since he'd last seen his mother. She'd vanished when they had vanquished Grima; or rather, when she had dealt the deathblow to the Fell Dragon. Crushed by his own hand, the beast had died permanently, but had dragged Queen Robin with him as he vanished.

While most of the other children had gone on their own way, including Lucina and her newly-titled boyfriend, Morgan hadn't really had any… ambitions of his own. He had just wanted to learn strategy from his mother, and with her gone, well… he'd been a little lost until Chrom had offered him a place in the palace. Not as his son, of course. The people would have their Exalt committed if he claimed fatherhood over a boy just a few years younger than him. Rather, Morgan had been named Chief Tactician of Ylisse in his absent mother's place, and had since then learnt from practice and served as Chrom's most trusted advisor. His memory still failed him on his life before he'd travelled through time to get here, but it barely weighed on him anymore. The loss of his mother was harsh, but he was close with his father and with his sister- even if she didn't know she _was_ his sister. It was better that way. Less confusing for both of them.

Surely, these new memories were far more valuable than the ones he had lost. He doubted those had contained anything more than trauma and horrors, anyway. He realigned his notebooks and maps so they wouldn't slip and took off, whistling to himself and resolving to get Chrom and Lucina's horses in order while they ate. Chrom had mentioned riding to Southtown for a little quieter a shopping trip than they could have in Ylisstol.

By the time they returned, it was well past dusk, and Lucina figured Severa was asleep so she'd have to get herself ready for the night. Fortunately, while she did use Severa's services most of the time, she was not so inept that she could not change into her own nightclothes. As she removed her boots and stockings, however, her eye was drawn to an ugly bruise on her ankle. Huh? But she hadn't hit her ankle on anything? Sitting on her bed, she lifted her foot and put it on the mattress, twisting it so she could see the outside of her ankle and the bruise more clearly. What was even weirder was that it didn't hurt when she pushed on it, like bruises were meant to do. She scratched her head. Well. That was… unusual. It was pretty big, too, and she could for the life of her not remember where she'd gotten it. Finally, she shrugged, resuming undressing. It wasn't readily visible, so no one would bother her about it until it healed on its own as bruises were wont to do. And if she did have to leave her ankle exposed, she could cover it up with the makeup powder Cynthia had given her a few days before as an early gift. It matched her skin tone perfectly and would be completely inconspicuous.

Strangely, though, it didn't heal on its own. If anything, it got weirder. Every evening, Lucina would wait for Severa to leave before she would pull up her foot and inspect it. If she didn't know any better, she could have sworn that it was slowly changing shape, its outline becoming sharper day by day as it reshaped itself into some sort of symbol. The longer this went on, the more disconcerting it became, and she took precautions to hide it from Severa for fear of what her friend would say about it. For the same reason, she couldn't ask Laurent if he'd read of any phenomena like it.

Maybe her father knew something? She doubted it, but he was her best guess. He'd always been good to her and wouldn't shun her over something silly like this. She left her room and hurried down the hallway to his. Hoping he wouldn't be asleep, she knocked on his door and waited, suddenly nervous. It didn't take more than a few seconds for him to reply. "Yes?" she heard him say, his voice clear. He hadn't been asleep, then.

Relieved, she heaved a sigh. "It's me, Father," she said. "There's something I want to ask you. It can't wait until tomorrow," she added, knowing he would ask that otherwise. She was a little old for night terrors. She heard his footsteps as he walked to the door and opened it, greeting her in his normal clothes and letting her in. A quick look at the writing table against the nearby wall told her enough- he'd still been working. "I'm sorry to interrupt…" she started, suddenly shy, but her father gestured that she needn't worry.

"It's alright. I'd much rather help you with whatever it is than read that letter one more time." He sat down on his bed, gesturing that she had to join him. "What ails my little angel, then?"

"This," she said, showing him her ankle and the bruise that had come to resemble a birthmark more than a bruise. "It just showed up a while ago and it won't go away! It doesn't hurt either, it's just… there."

Chrom hesitated, reaching out to touch it and gently taking hold of her ankle. "I see," he said, but she could practically hear the gears in his head turning. "Have you shown anyone else?" She shook her head. "Good. I don't know what this means, Lucina, but I'll talk to Morgan on the matter. He's, er… well-read. He might know more."

"About this? Are you sure?"

"Confident," he said, nodding as he let go of her ankle. "Don't worry about it for now," he reassured her as he ruffled her hair, "It'll be fine. Go to sleep, we'll see Morgan tomorrow."

"Yes, Father. Thank you."

She returned to her own chambers and slept soundly, but woke up early from a strange mixture of nervousness and excitement. She dressed herself hastily, not waiting for Severa to arrive, and almost ran from her room, heading for the wing of the castle where she knew Morgan's bedroom and study to be. He didn't live in absolute luxury like she and her father did, but he was given his own quarters so he could prepare for meetings and study in peace, without having to share space with other scholars. She knew he liked solitude when working. That said, she'd never actually visited his chambers, but she knew where they were. As she approached and reached for the door, though, she heard voices from behind it and stopped dead in her tracks.

One was the deep, warm voice of her father, and the other one was harder to hear because it was muffled by the door, but very recognizable as Morgan's. It looked like she wasn't the only one who'd gotten up early, then, she thought. Still, she waited, her hand on the doorknob. Her father hadn't come to get her… was this about something else? Should she be listening? Her curiosity got the better of her, and she put her ear to the keyhole in hopes of hearing better.

"I know what I saw, Morgan," she could decipher her father saying. "It wasn't fully formed yet, but I've seen that marking on your and Robin's hands so many times."

"I never said it wasn't possible," Morgan said, "Just that she showed you late at night after you had been working for a while. It's possible she really simply has a bruise and your sleep-addled mind made it out to be more than it is-"

"For crying out loud, Morgan!" She winced when she heard a loud bang. Her father must have slammed his hand down on something, perhaps Morgan's desk. "I was not hallucinating, Morgan! Your sister is growing the Mark of Grima on her ankle and I demand an explanation!" His sister? What? Lucina pulled her head back in confusion, but quickly resumed eavesdropping. Now, she was certain it was a good thing she hadn't walked in. "Robin had the mark and she lost her memories. You have the mark and you arrived amnesiac. Is Lucina in danger of forgetting everything, too?"

"I couldn't tell you." Morgan punctuated his words with a frustrated sigh. "Anything that happened regarding the mark in my time, I've forgotten. What I do know is this: Lucina always had it, too. The one with whom we fought side by side against Grima." Another Lucina? This was getting more confusing by the second. "And she never forgot, for better or for worse. So I don't think the mark in and of itself causes memory loss. If anything, I'm concerned that if she's inherited the mark, she may also have inherited other aspects of Grima." Grima?! The Fell Dragon! Lucina yelped, reeling back. She hadn't noticed it when Chrom had used the name in conjunction with the mark on her ankle because she'd been too confused about being referred to as Morgan's sister, but now she realized which Grima he meant. Surely that was nonsense?! She couldn't have anything to do with the god of destruction!

To her horror, the voices inside died down. She heard quick footsteps approaching the door, the click of the lock as it was unlocked, and then the door swung open, revealing a startled Morgan and Chrom. "Princess Lucina," Morgan began, "I… can explain." She didn't give him a chance, running off.

"How much do you think she heard?" He turned around to see Chrom looking concerned and a bit shameful. Perhaps discussing this first thing in the morning, within the walls of the castle, had not been the best idea. Of course, Morgan was equally as concerned for Lucina as his father was. When he'd been woken up at dawn by Chrom, who was _never_ up that early, he ought to have known something had been terribly wrong.

He shook his head. "Enough, I'd wager." Sighing, he sat down at his desk and rubbed his forehead. "We were stupid to think we could keep all this hidden from her. We knew how clever she is, and we knew Mother passed on certain things to her. The Mark is no exception."

"I had hope," Chrom muttered. "It took so long to appear. The Brand of the Exalt is visible from birth, I assumed the same was true for the Mark of Grima."

"I'm sorry, Father," Morgan said, leaning forward. "With Mother gone, I'm your only source on anything related to that side of the family, and I remember too little. I should have known. I should have warned you."

"And how would you have done that?" Chrom put his hand on Morgan's shoulder, giving him a kind smile. "It's as you say; you remember too little. Whatever took your memories when you arrived here is more stubborn than we thought, considering you still don't remember anything. You couldn't have warned me if you had wanted to." Sighing, he turned to the door. "I need to find her and tell her everything. She knows who Grima is. If she heard that much, who knows what state she's in."

"I'll go with you," Morgan hurriedly added as he got up. "It's my fault too."

They found Lucina in her own chambers, laying on her bed with a pillow clutched to her chest and Severa trying in vain to get her to calm down. Chrom dismissed the girl, telling her it'd be alright and they'd handle the situation, before sitting down on Lucina's bed with her. "Luci," he said, putting a hand on her back. "Come on, look at us."

She turned around, giving them a pointed glare. "I am _not_ related to the Fell Dragon," she stated, tears glistening in her eyes.

Morgan heaved a sigh. He wished it wouldn't have come to this for a long time yet. That being said. She was sixteen… formally, she was an adult. She had a right to know. "I'm sorry, Lucina," he said, prompting her to look up at him at his elision of her title. "You are. We both are. The only person in this room who has no blood relation to the Fell Dragon Grima is your father… And even he was involved with him, in a way."

"Nonsense!" she cried, sitting straight and clutching her pillow even more tightly. "The Fell Dragon is a monster and Father laid him low permanently! There's no way he's relevant to any of us!"

"Your mother did that." She paused at her father's voice, as did Morgan. Chrom had rarely spoken of Robin since her disappearance. He'd once confessed that it ached to think of her, and the moment she'd vanished haunted him in his dreams. It didn't help that Morgan took after her in many ways, and even Lucina had features that obviously came from her mother. Now, however, he steeled himself and continued. "Your mother was responsible for the Fell Dragon's fall; had I done it, he would have returned in a thousand years. That's why she's been gone for so long, Luci. She's quite simply… not here anymore." He shook his head.

Morgan continued. "Mother sacrificed herself so that we could live in peace, and not be threatened by the beast again so many years from now."

"And she was your mother too," Lucina said. It wasn't even a question. She was just stating what she knew from the conversation she'd overheard. "That's nonsense. You're almost as old as Father is. You can't be my big brother."

"I can prove it," Morgan said. The inner layers of his coat were always pulled tightly over the backs of his hands, but now, he started to undo them. "The marking that's started to appear on your ankle is something you inherited from her. She bore it on the back of her left hand, marking her out as a descendant of the Fell Dragon." He fully pulled back the coat, baring the back of his right hand and showing it to her. "I inherited it from her too, when I was born in my own timeline." Lucina grasped hold of his hand, examining the purple mark, showing the six eyes of Grima on their angular spiral, from every conceivable angle.

Finally, she let go. "That proves nothing," she said. "You're barely younger than Father, you couldn't possibly be-" She interrupted herself when Morgan turned around and dropped his coat entirely. The shirt he wore under it had a low neckline in the back, and under his neck, Lucina saw something else entirely. A blueish mark.

The same mark that was emblazoned on her right retina.

The Brand of the Exalt.

"No way…" She seemed to shrink into herself. It made no sense. Morgan pulled his coat back over his shoulders and fastened it over his hands again, sitting down on her other side. "But if you're- then- but how-"

He put a hand on her shoulder. "It's a very long story," he said.

"I don't have anything else to do today," she insisted, eyes still filled with tears, but more curious than angry now. "Tell your story."

Morgan took a deep breath. This would take a while.

He concluded his story by telling what had become of Robin- how she had vanished after killing the Fell Dragon, in spite of Chrom's wish to put it back to sleep so he wouldn't lose her. Lucina had gone quiet during his story, and he could see her struggling to comprehend and believe him. "That's…" she finally said, "A lot to take in."

"I know," Morgan admitted. Chrom had had to leave partway through to see to his duties, so it fell to him now to reassure her. "I know it's hard to believe. I didn't believe it myself, at first. If you want, I can get you into touch with your older self." She looked up at him, her expression difficult to read. Excitement? Fear?

"You'd do that?"

"Yes." He smiled. "She's been writing occasionally. I could tell her about you and ask her to drop by. Would that help?"

She shuffled on her bed, contemplating it. "Maybe. Do you think she'd like to meet me?"

"That depends," Morgan said, smiling. "Would you like to meet her?"

"Yes, of course!"

"Then, considering you're the same person, it's a safe bet she'd be happy to meet you."

Lucina beamed at him, but soon her smile faded and she frowned instead, looking at the mark on her ankle that looked just a little more defined than it had the night before. "So… You told Father that you worried I'd inherited more from Grima than just the mark… What did you mean by that?"

Morgan smiled. "It doesn't have to be anything dangerous. Like I said, our mother was able to act as a vessel for the Fell Dragon himself… but in me, the power only manifested as an ability to use dark magic. So if you've taken anything from Grima, it can be anything between the two. Maybe it's the reason you wreck so much when you're training."

"Nonsense," she said as he ruffled her already-messy hair, "Father does that too and the only involvement he had with Grima is that he married Mother."

"You and father are forces of nature in and of yourselves," Morgan said, laughing. "Come on. Let's write to yourself." He took her hand in his, squeezing it before she nodded, sat down at her desk, and pulled a piece of paper and a quill towards herself.

Almost a month later, she found herself summoned to the throne room while she was in the middle of covering the Mark of Grima to accommodate the shorter dress she wanted to wear. It was Morgan who came to fetch her; ever since the revelation that they were siblings –in a weird and contrived way, but siblings all the same- they had been much closer than before. In retrospect, Lucina realized that Morgan was much like their father in many ways, but also unlike him in many others- she supposed those were ways in which he took after their mother, and she'd grabbed the opportunity to learn as much about her as she had been able to.

Morgan told her about how he had seen their parents interact with each other as they walked to the throne room, but stopped abruptly as he pushed the large double doors open. In the middle of the throne room, Lucina saw her father embracing a woman his own age, with another, brown-haired man in mage's garb standing to their side, amused. The woman looked towards the doors when she heard them open, her face immediately lighting up as she saw Morgan. "Morgan!" she called, her voice clear and warm, "You look so incredibly well!" She hurried over and embraced him as well, kissing his cheek when they let go of each other.

She then turned to Lucina, still smiling. Lucina looked back at her, shaking with excitement and awe. She was _gorgeous._ Her blue hair hung down to at least her waist, and she had a super toned body, so she was clearly used to fencing and horseback riding, but her facial features were soft and she was aging more than gracefully. In one of her eyes, she bore the Brand of the Exalt. Lucina swallowed, finally recollecting herself and curtseying. "Um, hello…"

"Hello, Princess," the woman said, returning her curtsey with one of her own. "It's a pleasure to meet you, although I might know you better than anyone else does." She held out her hand. "I'm Lucina."


End file.
